California Map With County Boundaries

from urllib.request import urlopen
import json
with urlopen('https://raw.githubusercontent.com/plotly/datasets/master/geojson-counties-fips.json') as response:
    counties = json.load(response)

import pandas as pd
# ** the file below is hosted locally but I could alternatively write code that removes all the non-CA fip codes from the DF 
df = pd.read_csv("one_col_raw.githubusercontent.com_plotly_datasets_master_fips-unemp-16.csv",  
                   dtype={"fips": str})

import plotly.express as px

fig = px.choropleth_mapbox(df, geojson=counties, locations='fips',
                           color_continuous_scale="Viridis",
                           range_color=(0, 12),
                           mapbox_style="carto-positron",
                           zoom=4.7, center = {"lat": 37.0902, "lon": -120.7129},
                           opacity=0.5,
                           labels={'unemp':'unemployment rate'}
                          )
fig.update_geos(fitbounds="locations", visible=False)
fig.update_layout(margin={"r":0,"t":0,"l":0,"b":0})
fig.show()